In this task, you're given a question, a context passage, and four options which are terms from the passage. After reading a passage, you will get a brief understanding of the terms. Your job is to determine by searching and reading further information of which term you can answer the question. Indicate your choice as 'a', 'b', 'c', or 'd'. If you think more than one option is plausible, choose the more probable option to help you answer the question.

Example Input: Question: When was the man whose name is used as the unit of radio wave frequency born?  Passage:A modulated radio wave, carrying an information signal, occupies a range of frequencies. See diagram. The information (modulation) in a radio signal is usually concentrated in narrow frequency bands called sidebands (SB) just above and below the carrier frequency. The width in hertz of the frequency range that the radio signal occupies, the highest frequency minus the lowest frequency, is called its bandwidth (BW). A given amount of bandwidth can carry the same amount of information (data rate in bits per second) regardless of where in the radio frequency spectrum it is located, so bandwidth is a measure of information-carrying capacity. The bandwidth required by a radio transmission depends on the data rate of the information (modulation signal) being sent, and the spectral efficiency of the modulation method used; how much data it can transmit in each kilohertz of bandwidth. Different types of information signals carried by radio have different data rates. For example, a television (video) signal has a greater data rate than an audio signal.
 Links: a. Data signaling rate b. Carrier wave c. Hertz d. Audio signal
Example Output: c

Example Input: Question: On what day was the inauguration of the president who held a ceremony on the banks of the scenic New River to designate it as an American Heritage River? Passage:Ashe County has been home to, produced, or been visited by, several prominent people. It is the hometown of Monte Weaver from Helton who pitched for the Washington Senators and pitched a World Series game in 1933. After being traded from the Senators, he pitched for the Boston Red Sox, before being called into service in World War II. Weaver died in 1994. Albert Hash a well-known and beloved fiddler and instrument maker at one time resided in Lansing. Helen Keller visited an Ashe County native, Marvin Osborne, in 1944 when he was wounded in France in World War II. Loretta Lynn sang at the Central Food Market in West Jefferson in the late 1960s (the Central Food building formally housed a locally owned auto parts store and is now the location of a local restaurant). Roni Stoneman was a visitor to Ashe Park in the 1980s. In 1998, then-President Bill Clinton and his Vice-President, Al Gore, held a ceremony on the banks of the scenic New River to designate it as an American Heritage River. After the ceremony, both men had lunch at the historic Glendale Springs Inn, also located in Ashe County. Fiddle player G. B. Grayson was born in Ashe County in 1887.
 Links: a. Loretta Lynn b. Al Gore c. History of the Washington Senators (1901–1960) d. Bill Clinton
Example Output: d

Example Input: Question: How many caps did Fritz Walter have in the 1960 Champion's Cup? Passage:His club was Eintracht Frankfurt with whom he won the 1959 German Championship, and in 1960 reached the finals of Champion's Cup against Real Madrid. The left-footed Don Alfredo was the head of the team. Pfaff was a true playmaker with exceptionally good ball control and great skills at free kicks. Pfaff probably would have accumulated more than seven caps if Fritz Walter had not played the same role for West Germany as Pfaff played for Eintracht Frankfurt. In 1954, Atlético Madrid offered him 180,000 D-Mark but his wife Edith was against a move to Spain. Possibly Pfaff's greatest game was the 6–1 against Rangers F.C. in the 1959–60 semifinal first leg of the European Champion Clubs' Cup, which was followed by a 6–3 win of Eintracht Frankfurt in Glasgow in the second leg. He ended his career in 1962 at the age of 36.
 Links: a. Germany national football team b. Germany national football team c. Real Madrid CF d. Germany national football team
Example Output:
a

